Brussels Sprouts in Zone 6A — Mid-Atlantic

Brussels sprouts often get a bad rap, but homegrown ones are a completely different story! Their nutty, slightly sweet flavor is a welcome addition to fall and winter meals. Plus, they're surprisingly versatile – roasting, sautéing, or even shredding them for salads, you will find a way to love them! And let's be honest, there's something immensely satisfying about harvesting those little cabbages you grew yourself as the weather cools.

We definitely have our share of challenges here in the Mid-Atlantic – humidity, deer, and those pesky Japanese beetles. But don't let that scare you! With our 188-day growing season, and a little planning, growing great Brussels sprouts is totally achievable. The key is getting the timing right, and we'll walk you through it.

Starting Brussels sprouts indoors gives you a head start, especially important with their long growing season. You'll want to sow your seeds indoors from late February through mid March, about six weeks before you plan to transplant them outside. This helps them get a good start before our moderate Mid-Atlantic spring weather kicks into gear.

Use seed trays or small pots filled with a good seed-starting mix. Keep the soil consistently moist – bottom watering is a great way to prevent damping off. Place the trays in a warm spot (around 70°F) and provide plenty of light with a grow light or a sunny windowsill.

Remember, Brussels sprouts need a long growing season to mature properly, so starting them indoors is almost essential for a successful harvest in our region.

Once the danger of hard frost has passed (around mid April through early May), and your seedlings have a few sets of true leaves, it's time to transplant them outdoors. Before planting directly in the ground, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sunlight, wind, and temperature fluctuations.

Plant your Brussels sprouts 18-24 inches apart in rows. Give them plenty of space to grow. Watch for late frost warnings, and be prepared to cover your transplants if a cold snap is predicted.

Brussels sprouts need consistent moisture, especially during their early growth stages. In our humid Mid-Atlantic summers, it can be a bit of a balancing act – you don't want them sitting in soggy soil, but you also don't want them drying out. The ideal watering schedule will depend on rainfall, but aim to keep the soil consistently moist.

Stick your finger about two inches deep into the soil. If it feels dry, it's time to water. Generally, Brussels sprouts need about 1-1.5 inches of water per week, whether from rain or irrigation. Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our humid environment.

If the leaves start to wilt or turn yellow, you're likely underwatering. If the leaves are yellowing and the soil is constantly soggy, you might be overwatering. A layer of mulch around the plants can help retain moisture and suppress weeds.

Brussels sprouts can get quite tall and top-heavy, especially as those sprouts start to develop. A strong gust of wind can easily topple them over. Staking is essential to keep them upright and prevent damage.

Use sturdy stakes, such as bamboo or metal, and insert them into the ground near each plant when they reach about two feet tall. As the plant grows, gently tie the stalk to the stake with soft twine or plant ties. This will provide the support they need to withstand our Mid-Atlantic weather.

Pruning Brussels sprouts is pretty straightforward. As the sprouts start to develop from the bottom up, remove the yellowing or damaged lower leaves. This improves air circulation and directs the plant's energy towards sprout development.

About 3-4 weeks before you plan to harvest, top the plant by cutting off the top growth above the uppermost sprouts. This encourages the plant to focus its energy on maturing the existing sprouts. As we approach our first frost around mid- October, this topping will also help the sprouts mature before the cold weather sets in.

You can expect your first harvest of Brussels sprouts from mid July through late August, about 90 days after planting. The sprouts are ready to harvest when they are firm, tight, and about 1-2 inches in diameter. Start harvesting from the bottom of the stalk, twisting or cutting off the sprouts.

After harvesting the lower sprouts, the plant will continue to produce more sprouts upwards. Continue to harvest as they mature. The flavor of Brussels sprouts actually improves after a light frost, so don't be afraid to leave them in the garden as the weather cools.

As our first frost approaches in mid- October, harvest any remaining sprouts that are close to maturity. You can even cut the entire stalk and hang it upside down in a cool, dark place for later harvesting.

Aphids

• What it looks like: Clusters of tiny green, black, or white insects on stems and leaf undersides. You might also notice a sticky honeydew residue and curled or distorted new growth.
• What causes it: Aphids are sap-sucking insects that thrive in warm weather. They reproduce rapidly, and ant colonies often protect them in exchange for honeydew.
• How to fix/prevent it: A strong spray of water can knock aphids off plants. Encourage natural predators like ladybugs and lacewings. For heavy infestations, use insecticidal soap or neem oil. Avoid excess nitrogen fertilizer, which attracts aphids.

Cabbage Worms

• What it looks like: Smooth green caterpillars chewing irregular holes in leaves. You'll also see dark green droppings and white butterflies fluttering around your plants.
• What causes it: Cabbage worms are the larvae of white cabbage butterflies. They can have multiple generations per season in our warm climate.
• How to fix/prevent it: Bt spray is very effective against cabbage worms. You can also use floating row covers to prevent butterflies from laying eggs. Handpick caterpillars when you see them. Interplant with aromatic herbs like thyme and sage to deter the butterflies.

Loose Sprouts from Heat

• What it looks like: Instead of tight, compact heads, the sprouts are leafy and open.
• What causes it: High temperatures during sprout formation can cause them to loosen up.
• How to fix/prevent it: Choose heat-tolerant varieties. Provide consistent moisture to reduce stress on the plants. Mulch well to keep the soil cool. If a heat wave is coming, provide temporary shade.

Clubroot

• What it looks like: Stunted growth, wilting in the afternoon heat, and yellowing leaves. When you dig up the plant, you'll find swollen, distorted, and club-shaped roots.
• What causes it: Clubroot is a soil-borne disease that persists for many years. It favors acidic, wet soil.
• How to fix/prevent it: Raise the soil pH to 7.0-7.2 with lime. Improve drainage. Rotate brassicas on a 7-year cycle. Remove and destroy infected plants (don't compost them). Start transplants in sterile mix.

Mid-Atlantic Specific Challenges: Our moderate-to-hot summers and high humidity can create ideal conditions for pests and diseases that affect Brussels sprouts. Consistent monitoring and preventative measures are key to keeping your plants healthy and productive.

Companion planting can be a great way to improve the health and productivity of your Brussels sprouts. Green beans are great companions because they fix nitrogen in the soil, which helps Brussels sprouts grow. Celery can deter cabbage white butterflies, reducing the risk of cabbage worms. Onions also deter many pests with their strong scent. Potatoes don't compete for the same nutrients in the soil. Dill attracts beneficial insects that prey on pests.

Avoid planting tomatoes, strawberries, and peppers near Brussels sprouts. Tomatoes and peppers are susceptible to some of the same diseases as Brussels sprouts, increasing the risk of infection. Strawberries can attract slugs and snails, which can also damage Brussels sprouts.